A liquid boils when its vapor pressure equals the external pressure acting on the surface of the liquid. This is why water boils at a lower temperature at higher altitudes. This information is important for people who must design processes utilizing boiling liquids. Data on the vapor pressure P of water as a function of temperature T are given in the following table. From theory we know that ln P is proportional to 1/T . Obtain a curve t for P(T) from these data. Use the t to estimate the vapor pressure at 285 and 300 K.

T (K) .............. P (torr)
273 ................. 4.579
278 ................. 6.543
283 ................. 9.209
288 ............... 12.788
293 ............... 17.535
298 ............... 23.756